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Landed on my a**, stopping on a dime


JimB
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Lhotz has a measured peak power of 1200W, which I would think is also the reserve for a short lasting emergency braking. I have felt the Lhotz giving up shortly when braking very fast from something like 10km/h.

The one time I fell down on the Lhotz at speed was a long and pretty steep asphalt downhill that had a sudden drop. I was riding at near the max speed (which is 26km/h) and the Lhotz was not able to provide the power needed to brake so I landed on my back. Luckily I only got minor injury.

The power limits felt a bit too easy to reach so I upgraded to a KS-16S.

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1 hour ago, JimB said:

Hey all, note that I'm NOT blaming the wheel.  It did exactly as I would have expected.  I have purposely practiced stopping short to the point where the wheel has given out.  There's no mystery here.  I slammed it HARD into reverse and it buckled.  No skidding, batteries were probably at about 75%.  Basically, an overlean in reverse.  I was reasonably happy with the result - I stopped fast. 

Didn't think that.  I've had that happen twice stopping too fast and leaning back too much to try and go backwards.  It was a learning experience.  These wheels are not super powerful and will give up.:cheers:

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11 hours ago, JimB said:

Also, yes, I have been lusting after the KS-16S.  I just can't bring myself to shell out the cash.  I probably need to get 2 years out of the Lhotz, or my wife will give me a hard time.  I'm only at 10 months now.

Yes, kinda in the same situation right now, except that my extended battery makes it even harder justifying the purchase of a KS-16s. And then I'll have to deal with that tiny 2.125" tire of the 16S... still waiting on the details of the 2.5" tire mod @mrelwood made.

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Its the potential for situations like this that pushed me to get the GForm ski and board shorts with padding for the tail and sit bones. Falling on your backside can be a painful event. Again, glad you are OK and thanks for sharing the experience so we can all learn.

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I had a semi serious situation today whereby I was going down a long and steep grassy hill, with tree roots everywhere, and basically lost control and free wheeled down to the bottom being unable to lean back. I tried to a turn it down but every time I turned "into the wind" so to speak I'd slip or hit a bump, and so it was me bouncing all the way down with my weight completely on my wheels trying to slow down with no success at all. It felt exactly what I imagine a runaway wheel would feel like.

This has always been one of my fears and now that it has happened it's every bit scary. You have no control and you're just along for the ride as the wheel accelerates downhill, bumping along and your feet come off the pads.

It felt like Wild E Coyote trying to brake, even during the descent.

I always trolley my wheel down sketchy descents, going along exactly the path I map out and memorize, and usually a sketchy descent should be absolutely calm as every bit should go according to plan, but this backwards braking simply overwhelmed my skill on the wheel.

The pedals never buckled but the wheel felt like it suddenly stopped braking and never got those brakes back. It felt like some ABS was engaged and basically the wheel free wheeled all the way downhill until there was enough traction to "engage" the tire.

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On 24/09/2017 at 1:42 PM, Slaughthammer said:

Yes, kinda in the same situation right now, except that my extended battery makes it even harder justifying the purchase of a KS-16s.

I'm ever grateful for your superbly documented battery upgrade! Yet it didn't slow me down purchasing the 16S... Trust me, they leap is so monumental that I don't even consider them being in the same genre. It's a different hobby.

Just yesterday I took a short trip with the Lhotz. I tend to do a short medium strength braking to make sure my feet are not too forward. While doing this on the Lhotz a bit softer, I darned overleaned the bastard! I was able to hop away and keep upright while the Lhotz run to the bushes.

That wasn't even a medium braking for the 16S. The riding experience is so incredibly different with a powerful wheel.

On 24/09/2017 at 1:42 PM, Slaughthammer said:

still waiting on the details of the 2.5" tire mod @mrelwood made.

Dang, I'm sorry I've been lazy! I'll do my best to get it done this week.

On 25/09/2017 at 5:30 AM, LanghamP said:

You have no control and you're just along for the ride as the wheel accelerates downhill, bumping along and your feet come off the pads.

Man, feels horrible just imagining! I hope you get past the scared period soon.

This is one of the reasons I made shock absorbers for my 16S. We all have hit sudden bumps or otherwise had our feet slip or lose control. Having shock absorbers can ofcourse hugely increase comfort, but the major gain is that your feet stay on the pedals and your legs don't shake uncontrollably. Unfortunately I still haven't found a great method making them stay in place and not needing continuous adjustment.

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On 9/24/2017 at 10:30 PM, LanghamP said:

The pedals never buckled but the wheel felt like it suddenly stopped braking and never got those brakes back. It felt like some ABS was engaged and basically the wheel free wheeled all the way downhill until there was enough traction to "engage" the tire.

glad you made it ok! although i was kinda hoping you were going to say you parkoured off and then jumped back on to your tottering, not-yet-fallen wheel!

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Just now, kour said:

glad you made it ok! although i was kinda hoping you were going to say you parkoured off and then jumped back on to your tottering, not-yet-fallen wheel!

I did almost bail but I didn't have a strap. I was going down with the wheel like the captain of the Titanic!

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On 9/23/2017 at 5:21 PM, JimB said:

I did what someone here called a "power stop".  I leaned back hard and pushed back with my legs.  The wheel cut out due to overload/overlean.  I ended up on my butt (uninjured).  The wheel skidded forward a few feet (also uninjured).

yeah, coming up on those blind corners can be risky. what i worry about is my wheel becoming a projectile

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On 9/27/2017 at 8:05 AM, kour said:

yeah, coming up on those blind corners can be risky. what i worry about is my wheel becoming a projectile

I always use a safety strap.  Just a knotted strap looped through my belt.  It's not for me, or my wheel; it's to protect others.

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On 9/23/2017 at 4:32 PM, JimB said:

@mrelwoodI start each day down a steep (11 degree) 1/4 mile hill.  I ride at ~15 mph, just below the warning beeps, and haven't had a problem with controlling speed.  I *do* pay attention to the warnings though and never try to push past them to max speed.

Well crap!  After months with never an issue, coming down the hill fast (just below the warning beeps), I decelerated for my turn a little harder than normal.  (I have to turn left up a sloped curb near the bottom of the hill.)  I also had an extra 10 lbs of equipment in my backpack that I don't normally carry - which probably contributed.

Y'all know where this is going... braking was soft and I ended up on my butt again.  I'm riding more cautiously now - that is not a good feeling.  Bruised tailbone a bit - that'll be a nice reminder for a while.

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42 minutes ago, JimB said:

Well crap!  After months with never an issue, coming down the hill fast (just below the warning beeps), I decelerated for my turn a little harder than normal.  (I have to turn left up a sloped curb near the bottom of the hill.)  I also had an extra 10 lbs of equipment in my backpack that I don't normally carry - which probably contributed.

Y'all know where this is going... braking was soft and I ended up on my butt again.  I'm riding more cautiously now - that is not a good feeling.  Bruised tailbone a bit - that'll be a nice reminder for a while.

I hope that you are aware of the possible risk of overvoltage. Going downhill or braking strongly with a full battery will easily overload the battery/BMS due to the degenerative braking. I guess it depends on the device how abruptly this is handled, but worst case scenario is the wheel will just turn off without warning. I would be extremely careful if I had to start downhill with a full battery.

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7 hours ago, mrelwood said:

I hope that you are aware of the possible risk of overvoltage. Going downhill or braking strongly with a full battery will easily overload the battery/BMS due to the degenerative braking. I guess it depends on the device how abruptly this is handled, but worst case scenario is the wheel will just turn off without warning. I would be extremely careful if I had to start downhill with a full battery.

I use ChargeDoctor, and only charge to about 90%, for exactly the reason you describe.

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On 9/27/2017 at 8:57 AM, LanghamP said:

I did almost bail but I didn't have a strap. I was going down with the wheel like the captain of the Titanic!

Which wheel make/model was this?

I have yet to overpower a wheel and I'm 250 pounds.  I have done pendulum training with my Segway S1, and I have done one emergency downhill "avoid the bastard running the stop sign" evasion on my KS18S. So far, I've never been dropped. 

Ive fallen twice of my own fault, but never been dropped. 

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